The work described in this proposal will provide oral microbiological data for minority groups in the New York area. The data will pertain to dental caries and will involve a characterization of dental plaque and saliva with respect to the presence of certain types of potentially-cariogenic organisms. These will include, besides the more traditional organisms such as mutans streptococci, lactobacilli and actinomyces also the so-called "low-pH" non-mutans streptococci and Bifidobacterium. Based on our recent work, these organisms may also play a role in caries etiology. The microbial data in this "microbiology core" will under Aim 1 permit a further characterization of the oral health status of subjects belonging to different ethnic groups (see Project 1), the evaluation of the target organisms as a putative caries risk factor among other such factors for these ethnic groups (see Project 1), a between-ethnic group comparison of the levels of the target-organisms and comparison with their levels ill the white majority population, and a within-ethnic group evaluation of the correlation between the target organisms and caries. Data obtained for saliva from the same subjects (Aim 2) will be used for the same purposes. The levels of the target organisms in dental plaque from subjects belonging to different ethnic groups which will be obtained for mainly chemical analyses (Aim 3) in Project 4, will permit integration of microbiological and chemical information obtained for the same plaque samples.